Safety guard for centrifugal extractors



1932- T. A. BRYSON 1,841,086

SAFETY GUARD FOR CENTRIFUG'AL EXTRACTORS Filed Nov. 17. 1927 2 Sheets-Sheet 2 war/11111 49 y M A f VEVTOR. k Zm/L/ BY W! fln u ATTO EY Patented Jan. 12, 1932 UNITED STATES PATENT OFFICE TANDY A. BRYSON, 01' TROY, NEW YORK, ASBIGNOR, BY ASSIGNMENTS, TO TOLHURST MACHINE WORKS, mo, 01' TROY, NEW YORK, A CORPORATION OF NEW YORK SAFETY GUARD IOR CENTRIIUGAI. EKTRAGIORS Application filed November 17, 1927. Serial No. 838,997.

The invention relates to centrifugal extractors and more particularly to a novel and useful safety guard or cover for such extractors provided with means for automati- 5 cally preventing the starting of the extractor while the guard or cover is open.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts,

construction, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constitutlng a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings Fig. 1 is an elevation, with arts broken away, of the construction embo ying the mvention, the showing of the electric control circuit being partially diagrammatic;

Fig. 2 is a detail of the shift rod controlling latch partly in section and part in ele- .vation along line 2-2 of Fig. 1; and

Fig. 3 is a detail of the switch housing and circuit control partly in elevation and partly in-section.

The invention is directed to controlling and regulating the starting of centrifugal machines which are provided with safety guards or covers and provides a novel and extremely simple electrically controlled and operated mechanism for insuring that the rotatable basket of a centrifugal extractor cannot be set in motion until the safety cover is completely closed. p

In the operation of centrifugal extractors it has been found necessary to provide safety covers which will remain closed while the basket is rotating, so that it will be impossible for operatives to reach within the basket until it has come to a full stop. As a furtherv safeguard it is desirable to insure that the safety cover is securely closed before of the complicated, expensive and cumbersome nature of the installation.

The present invention provides a very simple, inexpensive and fool-proof electric guard interlock which is easily installed and can be so readily adapted to various types of centrifugal drive installations that its application in this field is practically universal.

In its present preferred embodiment the invention is shown as applied to a countershaft driven extractor, but it will be understood that the broad principles of the invention are equally applicable to other types of drives. The present embodiment comprises a centrifugal extractor of the underdriven type having a rotatable basket and a casing therefor provided with the usual safety cover, the s indle of the basket being driven by a flexible belt from a pulley mounted on a countershaft suspended from the ceiling. The countershaft is in turn driven by a be t from a suitable source of power and is provided with a tight and a loose pulley, the belt being shifted from one pulley to the other when the power is, to be applied or withdrawn. A latch member controlled by a solenoid plungernormally engages the belt shifting mechanism when the extractor is not rotating, so that power cannot be applied while the safety cover remains open; a gap in the energizing circuit for the solenoid being opened when the safety cover opens and closed when the safety cover is closed, so that upon closure of the safety cover it will be possible for the operator to close the energizing circuit by simply closing a switch therein. Energization of the solenoid releases the latch and permits shifting of the power belt to the tight pulley in order to start the extractor.

The foregoing general description, and the following detailed description as well, are explanatory and exemplary of the invention but are not restrictive thereof.

Referring now in detail to the embodiment of the invention, illustrated by way of example in the accompanyin drawings, a centrlfugal extractor is provl ed with a casing lwhich is supported by a general supporting structure 2, a rotatable basket 1a being mounted within the casing and supported on spindle shaft 3 Wind) is provided with a bearing housing 4. Means are provided for driving the spindle shaft to rotate the basket which as embodied comprise pulley 5 mounted also on the bearing hous ng and adapted to be driven by belt 6 whlch passes around directing fpulley 7 supported by bracket 8 extending rom the support 2 and thence upwardly and around driving pulley 9 which is mounted to rotate with countershaft 10. The countershaft 10 is supported in hanger boxes 11 which are suspended from the ceiling by brackets 12.

Power may be imparted to the counter-' shaft by a power belt 13, driven by any suitable driving mechanism. Mounted also on the countershaft 10 is a tight pulley 14 made fast to the countershaft so that it will rotate therewith by pin 15 and extending collar 16. A loose pulley 17 is mounted alongside the tight pulley on the countershaft and s adapted to revolve freely thereon so that 1ts revolution communicates no motion to the counter'shaft.

In accordance with the invention means are provided for shifting the power belt 13 from the tight pulley to the loose pulley and vice versa, when it is desired to apply or withdraw power from the countershaft. As

embodied, fingers 18, mounted on rod 19 which is slidably supported in the bracket guides 20 and 21, are adapted to shift the power belt 13 from the loose pulley to the tight pulley when the shiftrod 19 is moved to theleft (as viewed in Fig. 1) and back to the loose pulley when the shift rod is moved to the right. Bracket guides 20 and 21 may be conveniently suspended from brackets 12. A shifter arm 22 is provided'for moving the shift rod to the right or left, being suspended to rock' in pivot 23 attached to the ceiling, and having fastened to it arm 24 for engaging and moving the shift rod 19. For this purpose arm 24 is provided with a sleeved member 25 through which the rod 19 is adapted to pass, the right and left ends of sleeve 25 engaging respectively the lower end of bracket 21 and an enlarged portion 26 at the left end of shift rod 19.

In carrying out the invention, means are. provided for normally preventing movement of the shift rod 19 to the left so as to shift power belt 13 onto the tight pulley 14 for transmitting power to the countershaft and thereby starting the rotation of the extractor basket. As embodied, a latch mem ber 27, pivotally mounted in member 28 which is attached to the 1 lower portionof the shift rod engaging latch 27 to permit the,

power belt to be shifted to the tight pulley 14 when conditions are favorable for starting the extractor. As embodied, vertically extending rod 32 is attached to latch member 27 by loop 33 and is adapted to lift the latch from engagement with shoulder 30 on the shift rod 19. For this purpose rod 32 forms the plunger for solenoid 34 which is suspended from the ceiling in a suitable casing 35.

Referring now to the electrical circuit for energizing the solenoid 34, a battery or other suitable source of electric power, 36 is connected by feed wires 37 and 38 to the solenoid.

Both circuit wires 37 and 38 lead to a switch housing 39 which is mounted adjacent the centrifugal-casing 1 and supported by suitable means such as bracket 40. Wire 37 is provided with a contact terminal 41 supported within the switch housing by an insulated mounting 42. A resilient conductor member 43 is mounted at 44 in the upper portion of the switch housing and extends-downwardly from the mounting so that its contact terminal 45 is normally spaced apart from the contact terminal 41. The other end of conductor member 43 extends substantially horizontally from support 44 to engage the upper contact terminal of push-button switch 46, which is normally held in open circuit position by the upwardly acting resilient tendency of the conductor member 43. The lower contact terminal 47 for the switch is supported in the housing by the insulated mounting 48 and forms the terminal for circuit-wire 38 of the solenoid energizing circuit.

In accordance with the invention, the open-' ing and closing of the energizing circult is controlled by the movement of the safety cover 49 of the centrifugal extractor. As embodied, cover 49 is hinged to the centrifugal casing 1 by rod 50 which extends beyond the casing and is provided with a finger 51 which projects at right angles from the outarcuate movement of finger 51 as the cover is Y I opened and closed.

Briefly summarized, the operation of the i left to close gap 41-45. If switch 46 is now above-described mechanism is as follows':

Assuming the safety cover of the extractor to be in the open position and the power belt hook 31 of latch 27 whereby an attempt on the part of the operator to move-the belt 13 onto tight pulley 14 to start the extractor will be ineffective. An attempt to close the energizing circuit by switch 46 to cause the solenoid 34 to lift the latch and release shift rod 19 will be defeated because of the open gap 41-45. When, however, the safety cover is closed, finger 51 moves conductor 43 to the closed the circuit will be complete and the solenoid 34 will be energized to raise plunger 32 and consequently release the shift rod 19 so that the extractor may be started.

The invention in its broader aspects is not limited to the s ecific mechanisms shown and described but epartures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is 1. In centrifugal extractors in combina tion a rotatable basket, a basketcasipg with a safety cover thereon, driving means for rotating the basket, a control member for applying power to the driving means to start the rotation of the basket, a latch for preventing movement of the control member to start the basket, and electrically operated means for momentarily releasing the latch to permit movement of the control member I and starting of the basket when the safety cover is closed.

2. In centrifugal extractors in combination a rotatable basket, a basket casing with a safety cover thereon, driving means for rotating the basket, a control member for applying power to the driving means'to start the rotation of the basket, a latch for preventing movement of the control member to start the basket, and electrically operated means controlled by the movement of the safety cover and by the operator for releasing the latch to permit starting of the basket when the safety cover is closed. o

3. In centrifugal extractors in combination a rotatable basket, a basket casing with a safety cover thereon, driving means for rotating the basket, a control member for applying power to'the driving means to startthe rotation of the basket, means for preventing movement of the control member to.

start the basket, electrically operated means for releasing the control member to permit starting the basket, an electric circuit for energizing said releasing means and means for preventing closure ofthe energizing circuit when the safety cover is open.

4. In centrifugal extractors in combination a rotatable basket, a basket casing with a safety cover thereon, driving ,means for rotating the basket, a control member for applying power to the driving means to start the rotation of the basket, means for preventing movement of the control member to start the basket, electrically operated means for releasing the control member to permit starting the basket, an electric circuit for energizing said releasing means 'and means actuated by the closing of the safety cover for making possible closure of the energizing circuit whereby the basket may be set in motion.

5. In centrifugal extractors in combination a rotatable basket, 'a basket casing with a safety cover thereon, driving means for rotating the basket, a control member for applying power toithe driving means to startthe rotation of the basket, means for preventing moveme'ntof the control member to start the basket, electrically operated means for releasing the control member to permit starting the basket, an electric circuit for energizing said releasing means, a normallyopen gapin the circuit, a normally open switch in series with said gap, and

means actuated by the closing of the safety cover for closing the gap whereby the closing of the switch will be efliective to close the circuit and thereby release the control member for starting the basket. I

6. In centrifugal extractors in combination a rotatable basket, a basket casing with a safety cover thereon, driving means for rorotating the basket, a control member...for...

applying power to the driving means to start the rotation of the basket, means for preventing movement of the control member to start the basket, a solenoid operated plunger for releasing the control member to permit starting the basket, an electric circuit for energizing the solenoid and means for preventing closure of the energizing circuit when the safety cover is open.

8. In centrifugal extractors in combination a rotatable basket, a. basket casing with a safety cover thereon, driving means for rotating the basket," a control member for applying power to the driving means to start the rotation of the basket, means for preventing movement of the control member to L start the basket, a solenoid operated plunger Y for releasing the control member to permit 5 starting the basket, an electric circuit for en- 7 ergizing the solenoidand means actuated by the closing-of the safety cover for making i possible the closure of the energizing circuit whereby the basket may beset in motion.

In testimony whereof, I have signed my name to this specification.

TANDY A. BRYSON.

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